/* 通用样式 */
:root {
    --primary-color: #1890ff;
    --secondary-color: #52c41a;
    --text-color: #333;
    --light-text: #666;
    --border-color: #e8e8e8;
    --bg-color: #fff;
    --section-bg: #f5f5f5;
    --hover-color: #40a9ff;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background: var(--bg-color);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏样式 */
.nav {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.08);
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
    transition: all 0.3s ease;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.logo:hover {
    color: var(--secondary-color);
    transform: translateY(-1px);
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 30px;
}

.nav-menu li {
    position: relative;
}

.nav-menu a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    padding: 8px 0;
    transition: all 0.3s ease;
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
    box-shadow: 0 1px 2px rgba(24, 144, 255, 0.2);
}

.nav-menu a:hover {
    color: var(--primary-color);
    transform: translateY(-1px);
}

.nav-menu a:hover::after {
    width: 100%;
}

/* 当前页面选中效果 */
.nav-menu a.active {
    color: var(--primary-color);
    font-weight: 600;
}

.nav-menu a.active::after {
    width: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 8px 24px;
    background: var(--primary-color);
    color: white;
    border-radius: 4px;
    text-decoration: none;
    transition: background 0.3s;
    border: none;
    cursor: pointer;
}

.btn:hover {
    background: var(--hover-color);
}

/* 卡片样式 */
.card {
    background: var(--bg-color);
    border-radius: 8px;
    padding: 24px;
    box-shadow: var(--shadow);
    margin-bottom: 24px;
}

/* 网格布局 */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
    margin: 24px 0;
}

.feature-card {
    background: var(--bg-color);
    border-radius: 8px;
    padding: 24px;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
}

/* 页脚样式 */
.footer {
    background: var(--section-bg);
    padding: 40px 0;
    margin-top: 60px;
    text-align: center;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        padding: 10px;
    }

    .nav-menu {
        margin-top: 15px;
        gap: 15px;
        flex-wrap: wrap;
        justify-content: center;
        background: rgba(255, 255, 255, 0.98);
        padding: 10px;
        border-radius: 8px;
        box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    }

    .nav-menu a {
        font-size: 14px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.section {
    animation: fadeIn 0.6s ease-out;
}

/* 标题样式 */
.section-title {
    text-align: center;
    margin-bottom: 40px;
    color: var(--primary-color);
    font-size: 2.5em;
    position: relative;
    padding-bottom: 15px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: var(--primary-color);
}

/* 动画类 */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: var(--transition);
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 响应式布局 */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .section-title {
        font-size: 2em;
    }
}